Steam-engine valve



2 Sheets-Shet 1,

(No M0881.)

J. HEATH.

STEAM ENGINE VALVE.

'Patented Aug. 28, 1888.

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2 Sheets- Sheet 2.

(No Model.)

J.HEATH.

STEAM ENGINE VALVE.

No. 388,414. Patented Aug. 28, 1888.

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UNITED STATES PATENT OFFICE.

a JOHN HEATH, OF JANESVILLE, WISCONSIN.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters Patent No. 388,414, dated August 28, 1888.

Application filed February 14, 188B. Serial No. 263.954. (No model.)

.To au whom t may concern:`

Beit known that I, J oHN HEATH, a citizen of the United States, residing at Janesville, in the county of Rock and State of Wisconsin, have invented certain new'and useful Improvements in Steam-Engine Valves; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and usethe same.

My invention relates to the construction and operation of the valves of steam-engines, more particularly the slide-valves of reciprocating engines, and belongs to engines of the class employing two valves movable in opposite directions in opening and closing the steamports.

The object of my invention is to improve the construction of such valves and their operating-gear, whereby a greatly-improved valve mechanism is attained. The nature and advantages of my improvements will more clearly appear by the following description in detail of the best way now known to me of embodying them, and the subject-matter claimed by me as of my invention will be distinctly recited at the close of this specification'. Idesire it understood here at -the outset also that some of my improvements may be used Without the others, and in machinesl differing from that herein particularly described.

The accompanying drawings show so much of a valve mechanism and its operating-gear as is necessary to illustrate my improvements, and in said drawings, Figure l is a side View,

` partly in elevation and partly in section, of

my improved valve and operating-gear with the steam-ports closed. Figs. 2 and 3 are longitudinal central sectional views of the steam-chest, showing the double valve in its extreme positions on the valve-seat, with the right and left hand or forward and back ports to cylinder unelosed, respectively; and Fig. 4 is a transverse section thereof, showing more particularly the arrangement of the steamrelieving anti-friction plates and the valveports omitted. Fig. 5 is an end view of the rocker-arm which operates the valves, with a portion of its connections shown in dotted lines. Fig. 6 is a transverse section through the operating-connections on the line 6 6 of Fig. 1, showing more particularly an end view of the bracket 'and connections in advance of the rocker-arm.

My improved valve consists of two oppositely-movingparts;aloweror main valve, A, provided with entrance-ports a a' and an eX- haust-port, a2, and an upper valve, B, moving on said lower valve, A, and provided with an exhaust cavity or port, b. rlhis double valve is inclosed by aud moves in the steam-chest G, as usual, and said chest maybe supplied with steam in the usual manner. The valves A B are so constructed and are operated in such a manner by my improved gearing or operatingconnections that when the right hand or forward port, d, of the cylinder I) is opened for the admission of steam to the cylinder, which occurs when ports a and d coincide, the back or left-hand cylinder-port, d', and port a/ of the valve A also coincide; but the entrance of steam therethrough is prevented by the position of the upper valve, B, which covers said port a of the valve A, and at the same time opens the cavity or exhaust-port arl of valve A, so as to permit of the exhaust of the steam through the exhaust-port ai of valve A and out through the exhaust-port d2 of the cylinder D. The lower ends of the port-openings a a. ofthe main valve A, next to the cylinder D, are or may be cut away or enlarged to insure a full opening of the ports d d of said cylinder when only a half-stroke of said valve has been made, which is all that is necessary for a full opening of said ports d d', because of the upper valve, B, having been also moved the same distance, but in the opposite direction, thereby covering or uncovering the ports a a', as the case may be, and alternately opening and closing the cylinder-ports d d 1n about half the time required by a single sliding-valve.

Instead of using two separate sets of gearing or connections, one for each valve, for moving the upper and lower valves simultaneously in opposite directions,Iprefer to use a single mechanism, and to this end have invented a simple gearing or operating-connection, whereby both valves may be moved in opposite directions simultaneously, one upon the other, by one main rocker-arm and its connections. To this end, therefore, I preferably employ a rocker-arm, E, rocking on IOO its axis e in suitable bearings, which may be actuated by an eccentric and gearing,as usual, such actuating-connections, however, not being shown in the drawings, as they may be of anyweil-known suitable construction. Iivotally connected to the rocker-arm E at its crank end c is the upper valve stem or rod, F. The lower valve rod or stem, G, is pivotallyjointed atg to the lower end of a beam or arm, H, fitted to rock on an axis, 71extending from a bracket-frame, I, suitably mounted on the engine-frame. Said beam or arm H is connected at its upper end, h', to the rockerarm E by a link, J, having a knuckle-jont,j,at

Yone end and a rocking jointd", at the other,

whereby there is a yielding operating linkconnection between the rocker-arm E and rocking beam H.

To bring the valve-rods F G in vertical line with each other,I provide the arm or beam H with an opening, ,therein,through which the rod F may pass.

The beam or arm H may be mounted either in front or behind the main rocker-arm E, the result being the same in either case; but I have shown said beam H in front of the arm E. It will thus be seen when the valves are in their central position, asin Fig. 1, that if the rocker-arm E is rocked backward on its axis e the beam H will follow, and consequently thrust the main or lower valve,A,forward a half-stroke to cause the ports a d to coincide. These ports a d, in fact, already coincided by reason of the enlargement of the lower end of the port a, but the position of valve B then prevented the entrance of steam therethrough. Obviously, at the same time that the valve A is thrust forward the valverodF is moved backward by its connection with the rocker-arm E, and consequently moves the upper valve, B, backward also a halfstroke, thereby entirely uncovering or opening the port e of the main valve A,which, as has already been said, was moved forward a half-stroke. This movement of the two parts of the valve by their operating-connections is sufficient to open the ports a and d so as to freely admit steam through said ports into the cylinder D, the steam already in said cylinder at the opposite side of the piston being exhausted through the exhaust-ports d, a', b, a2, and d?. The next movement of the rocker-arm E in the opposite or reverse direction of course reverses the movement and direction of the valves A B relatively to each other and to the ports of the cylinder, so as to permit steam to enter at the opposite side and be exhausted from the opposite side of the cylinder thereto, as before.

The valve-stems are provided with suitable means-such as tu r11-buckles, for example-for properly adjusting the positions of the valves, and so as to admit a greater or lesser quantity of steam for regulating the speed of the engine.

I have described the two valves as moving the same distance. This is not necessary,

however,as one maybe fitted to move a greater distance than the other, and such fitting of the valves is even desirable in certain instances. For instance, if the whole travel of the two val ves is equal to eight inches, the upper valve may be fitted to travel five inches and the lower valve travel three inches; or, if the throw of the eccentric and upper valveis four and one-half inches, the lower valve may be made to travel three and one-half inches. This may be desirable owing to different sizes of cylinders and kinds of valve-seats and ports.

To relieve the valves of the pressure of the steam and the consequent f rictionwto which they are thereby subjected, (the steam in said chest pressing down upon the valves and causing friction between the valves and the valveseat, upon which the valves slide in opening and closing the ports to the cylinder,) I preferably mount a rigid plate, K, just above said valves to take the pressure of the steam and enable the valves to work comfortably and without friction. Said steam-plate K is supported by two side plates, KK2,one placed on each side of the valves, but not close enough thereto to interfere with the easy working thereof, and bolts 7a k may be passed through said steam-plate K, outside said side supporting-plates, KK2,into the top ofthe cylinder to secure the parts firmly in the desired position within the steam-chest. These plates K K K2 do .not interfere with the admission or exhaustion of steam, but insure the easy working of the valve,effectively relieving said valve from all or almost all the friction arising from the pressure of the steam thereon. This improvement in'r'elieving the valve from steam-pressure is of course applicable as well to single as to the type of double or two-part valves I have shown, and it can be used to advantage upon or with all kinds of slide-valves.

The valves are supplied with oil, as usual, and the plate K may be perforated for that purpose.

I am aware that it is not broadly new to employ two valves moving simultaneously in opposite directions; but

What I claim is- I. The combination of the two-part valve, the lower valve having two steam-inlet ports and an exhaust-port,and the upper valve having an exhaust port or passage therein, in combination with the cylinder having two entrance-ports and an exhaust-port and operating-connections to move said valves simultaneously and in opposite directions with respect to each other in admitting and exhausting steam, substantially as described.

2. The combination of the two-part valve, the single rocker-arm, and the intermediate connections,substantially as dcscribed,where by the parts of said valve are moved simultaneously and in opposite directions with respect to each other.

3. The combination, in Va two-part valve- ICO IIO

plate rigidly supported above said Valve, the I5 side supporting-plates of said steam-plate,and the fastening-bolts securing said steam-plate and side plates together around the valve and passing through said steamplate outside said side supporting-plates and into the cylinder- 2o face, substantially as described.

In testimony whereof I ax my signature in presence of two witnesses.

JOHN HEATH.

Witnesses:

GEO. G. SUTHERLAND, J osEPH B. Don, Jr. 

